package com.spring.boot.mvc.web;

import java.util.HashSet;
import java.util.Set;

public class PathController {

    public static void main(String[] args) {
        Set<String> a = new HashSet<>();
        a.add("111");
        a.add("222");
        a.add("333");

        Set<String> b = new HashSet<>();
        b.add("111");
        System.out.println(a.containsAll(null));
    }
}
